Question

What if the department store from problem #2 wanted to know how many customers they would...

What if the department store from problem #2 wanted to know how many customers they would have to sample from to have a .99 probability that the sample proportion is within .05 of the population proportion. Recall that the previous sample proportion was 30/120 or 0.25.

Math   Statistics-And-Probability   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

Solution,

Given that,

= 0.25

1 - = 1 - 0.25 = 0.75

margin of error = E = 0.05

At 99% confidence level

= 1 - 99%

= 1 - 0.99 =0.01

/2 = 0.005

Z/2 = Z0.005  = 2.576

sample size = n = (Z / 2 / E )2 * * (1 - )

= (2.576 / 0.05)2 * 0.25 * 0.75

= 497.68

sample size = n = 498

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
An automobile manufacturer would like to know the proportion of its customers that are not satisfied...
An automobile manufacturer would like to know the proportion of its customers that are not satisfied with the service provided by the local dealer. The customer relations department intends on surveying a random sample of customers to estimate this proportion within 1.5 percentage points at 99% confidence. Past studies suggest that the proportion of unsatisfied customers will be about 20%. Find the minimum number of customers that should be included in the survey.
1. 60% of a department stores customers have a credit card from that department store, and...
1. 60% of a department stores customers have a credit card from that department store, and 30% of a store’s customers make at least 1 purchase per month on average. Finally, 80% of the customers who make at least 1 purchase per month have a store’s credit card. Of the customers who do not make at least 1 purchase per month, what is the probability a randomly chosen customer has a store’s credit card? (please round your answer to 4...
Suppose the manager of a shoe store wants to determine the current percentage of customers who...
Suppose the manager of a shoe store wants to determine the current percentage of customers who are males. How many customers should the manager survey in order to be 99% confident that the estimated (sample) proportion is within 5 percentage points of the true population proportion of customers who are males? z0.10 z0.05 z0.04 z0.025 z0.01 z0.005 1.282 1.645 1.751 1.960 2.326 2.576 Use the table of values above.
In examining the credit accounts of a department store, an auditor would like to estimate the...
In examining the credit accounts of a department store, an auditor would like to estimate the true mean account error (book value – audited value). To do so, the auditor selected a random sample of 50 accounts and found the mean account error to be $60 with a standard deviation of $30. a. Construct a 95% confidence interval for the population mean account error. What conclusion can be made from this confidence interval? b. How large a sample is actually...
6.20. A convenience store owner wants to know how long his customers spend browsing the store...
6.20. A convenience store owner wants to know how long his customers spend browsing the store before making a purchase. It is found that time spent is normally distributed with an average of μ = 5 minutes and a standard deviation of σ = 2.2 minutes. Using a random sample of 14 customers, what is the probability that a customer, on average, will spend less than 4 minutes browsing the store? 6.21. It is estimated that 66% of new businesses...
An automobile manufacturer would like to know what proportion of its customers are dissatisfied with the...
An automobile manufacturer would like to know what proportion of its customers are dissatisfied with the service received from their local dealer. The customer relations department will survey a random sample of customers and compute a 95% confidence interval for the proportion that are dissatisfied. From past studies, it believes that this proportion will be about 0.3. Find the sample size needed if the margin of error of the confidence interval is to be no more than 0.045. (Round your...
An automobile manufacturer would like to know what proportion of its customers are dissatisfied with the...
An automobile manufacturer would like to know what proportion of its customers are dissatisfied with the service received from their local dealer. The customer relations department will survey a random sample of customers and compute a 95% confidence interval for the proportion that are dissatisfied. From past studies, it believes that this proportion will be about 0.27. Find the sample size needed if the margin of error of the confidence interval is to be no more than 0.04. (Round your...
The marketing department of a manufacturing company wanted to find out how many blank video cassettes...
The marketing department of a manufacturing company wanted to find out how many blank video cassettes are purchased by the average American each year. The data for a random sample of Americans are as follows: 7, 0, 6, 3, 10, 0, 4, 9, 6, 3, 12, 0, 5, 1, 8, 6 (n = 16). What are the limits of the 99% confidence interval for the mean of the population? PLEASE SHOW ALL WORK!
2. The manager of a grocery store has taken a random sample of 100 customers. The...
2. The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took the customers in the sample to check out was 3.1 minutes. The population mean is 3.5 minutes and the population standard deviation is known to be 0.5 minutes. We would like to know if there is evidence of a change in average check out time. Explain in the context of this question what a type 1 error would...
A grocery store is trying to predict how many packages of toilet paper rolls will be...
A grocery store is trying to predict how many packages of toilet paper rolls will be purchased over the next week. They know from their records that each customer has a 60% chance of buying 0 packages, a 30% chance of buying 1 package, an 8% chance of buying 2, and a 2% chance of buying 25. They expect about 150 customers per day. a. What is the expected number of packages sold in one day? b. What is the...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT